1. Field of the Invention
This invention relates to a portable electric circular saw, more particularly to an electric circular saw of the type being powered by a rechargeable battery incorporated therein.
2. Description of the Prior Art
Portable electric saws have been designed in the past with a fixed handle projected atop the housing in which the motor for driving a saw blade is accomodated, as disclosed in U.S. Pat. No. 3,056,439. However, saws of this type necessitate an AC power supply and, therefore, rely on a power cord which is to be plugged into a conventional household electrical outlet or an electrical outlet provided in an operation location, limiting the use of the saw to restricted locations where the power cord can reach an electrical outlet. Moreover, the power cord extending from the saw may cause inconvenience, such as the cord detracting from cutting operation of the saw or being inadvertantly cut by the saw blade in use. To eliminate the above inconvenience, a portable saw powered by an incorporated battery is desirable. The battery employed for this kind of saw requires a relatively high capacity to enable powerful sawing by the motor and thus is preferred to be a lead storage battery, as has been adapted to motor vehicles and the like. This lead storage battery is of heavy weight, however, and despite its advantageous nature of being rechargeable, would require a sturdy saw structure for the purpose of providing easy hand control of the sawing operation, so as to achieve balance of the whole saw device in the direction along which the lead storage battery and the motor are aligned, that is, lengthwise balance along a cutting line disposed in line therewith.